This poper descrihes a method for linking the AUTOCAD Drafing Package ('AUTOCAD'). a well-known computer-aided design sofrware package for arehiteets, with an acoustic ray-tracing program, in detail. Two application ptograms. EXTATTDX and EXTVERTE. have been worked out to retrive useful information for a ray-tracing program from the drawing files of AUTOCAD. The flow chart of the EXTATTDXD program and some application examples are given. This linking not only speeds up the acousties andalysis proeess for a rariety of halls, but also enables us to test the acoustic properties for buildingx at design stage. The retriered information can also be used for other application purposes.

By summing up the opinions of many experts about concert hall acoustics, this paper suggests a more complete factor set and more detailed membership functions for the fuzzy set evaluation of concert hall acoustics. The mean forte sound-pressure level LpF representative of subjective loudness, is introduced in the factor set in addition to those already considered previously.

Loudness is one of the most essential parameters for assessing the acoustical quality of an auditorium. But owing to the lack of an authentic criterion, it remains unresolved how to evaluate the loudness in concert halts. In this paper LpF, the mean forte sound pressure level of tutti-sound is suggested as a criterion to describe the loudness in a hall. The prediction procedure of the LpF value distribution in a hall is demonstrated, Comparison between predicted and measured LpF levels is given. Tentative optimum and allowable LpF values for concert halls are also doscissed.